A plane leaves an airport traveling at 400 mph in the direction N 45° E. A wind is blowing at 40 mph in the direction N 45° W. What is the ground speed of the plane? 400 mph
402 mph
429 mph
440 mph

402 mph

Step-by-step explanation:

Draw a right triangle with 400 and 40 as the two legs.

You know this is a right angle because 45 degrees NE is perpendicular to 45 degrees NW. (imagine a compass)

So, the two side lengths are 400 and 40

Using the Pythagorean theorem, (a^2 + b^2 = c^2) you can see that the answer is 401.995, or 402

B

Step-by-step explanation:

x/3-10=8

x/3=18

x=48

linear pair postulates